As demand on the world's communication networks increases, new protocols emerge. One such protocol is called Generalized Multi-Protocol Label Switching (GMPLS). GMPLS enhances the MPLS architecture by separating the control and data planes of various networking layers. GMPLS enables a seamless interconnection and convergence of new and legacy networks by allowing end-to-end provisioning, control, and traffic engineering.
A label-switched path (LSP) may be subject to local (span), segment, and/or end-to-end recovery. Local span protection refers to the protection of the channel (and hence all the LSPs marked as required for span protection and routed over the channel) between two neighboring network nodes. Segment protection refers to the recovery of an LSP segment between two nodes (i.e., the boundary nodes of the segment). End-to-end protection refers to the protection of an entire LSP from the source node to the destination node.